JP2007286118A - Imaging apparatus and its control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an image focused at a position intended by a photographer just by recording the image of a subject by photographing operation performed once even if there exist a plurality of subjects in different distances. <P>SOLUTION: The imaging apparatus includes: a focus lens 101 for adjusting a focus; a focus lens driving motor 103 and a focus lens driving circuit 104 for driving the focus lens 101; an imaging device 112 for photoelectrically converting the subject image formed through the focus lens 101; an image processing processor 115 extracting the high-frequency component of a luminance signal obtained from the imaging device 112; a system control CPU 119 for controlling the movement of the focus lens 101; and a cross switch 131 and a peak position moving switch 132 capable of selecting an optional maximal value position of the high-frequency component when there exist a plurality of maximal value positions of the high-frequency component extracted by the image processing processor 115. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an imaging apparatus such as an electronic still camera having a focus adjustment function, a method for controlling the imaging apparatus, and a computer program.

  In an electronic still camera, a video camera, or the like, a system is used in which a lens position at which a high frequency component (referred to as a “focus evaluation value”) of a luminance signal obtained from an image sensor such as a CCD is maximized is set as a focus position. . For example, there is a hill-climbing method in which the lens is moved in a direction in which the focus evaluation value obtained from the image sensor increases, and the lens position where the focus evaluation value is maximized is the in-focus position. Further, there is a scanning method in which the focus evaluation value is stored while driving the lens over the entire range of ranging, and the lens position where the stored value is the maximum is the in-focus position.

  In these methods, as shown in FIG. 16, a method is known in which the central portion of the shooting screen is a distance measuring frame, and the lens position where the focus evaluation value is the maximum for a subject within this range is the in-focus position. Yes. Also, as shown in FIG. 17, after setting a plurality of distance measurement frames and storing a focus evaluation value for each distance measurement frame, a lens position that maximizes the focus evaluation value is obtained for each distance measurement frame, A method of determining a position where the lens is finally moved from these lens positions is known.

  By the way, if there are no subjects with different distances in the distance measurement frame as described with reference to FIGS. 16 and 17, the relationship between the lens position and the focus evaluation value has a mountain shape as shown in FIG.

  However, when there are a plurality of subjects at different distances within the distance measurement frame, the relationship between the lens position and the focus evaluation value is as shown in FIG. That is, since the peak of the focus evaluation value appears for each subject at different distances, if there are two subjects at different distances in the distance measurement frame, peaks appear at two different lens positions.

  In this case, since the camera cannot determine which subject the photographer originally wants to focus on, it is possible to move the lens by selecting a position corresponding to the closest distance among a plurality of peak positions. Many. However, in that case, for example, when shooting through the wire mesh, the wire mesh is focused, and the subject beyond the wire mesh originally intended by the photographer is not focused. Even if the camera is not focused on the closest position, the camera cannot determine to always focus on the position intended by the photographer.

  As a technique assuming that there are a plurality of subjects with different distances in the distance measurement frame as described above, for example, there is an imaging apparatus disclosed in Patent Document 1. Patent Document 1 proposes storing a focus lens position indicating peak positions of a plurality of focus evaluation values corresponding to different subjects, and photographing at each stored focus lens position.

JP 2003-333411 A (page 14, FIG. 4, FIG. 5)

  However, as disclosed in Patent Document 1, if a plurality of images with different in-focus distances are captured in one shooting operation, the total capacity of the recorded images for one shooting operation is enormous. It becomes a thing.

  In addition, since an image unintended by the photographer is also recorded, there is a lot of waste, and it takes time and effort to confirm an image after photographing, delete an unnecessary image, and the like.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a position intended by a photographer only by recording one image in one photographing operation even when there are a plurality of subjects at different distances. It is to make it possible to obtain an image in focus.

The imaging apparatus of the present invention includes a focus lens that performs focus adjustment, a focus lens driving unit that drives the focus lens, an imaging unit that photoelectrically converts a subject image formed through the focus lens, and the imaging unit Extraction means for extracting high-frequency components of the luminance signal obtained from the control means, control means for controlling movement of the focus lens via the focus lens driving means, and a plurality of maximum value positions of the high-frequency components extracted by the extraction means It is characterized in that it has an operation means that can select an arbitrary maximum value position when it exists.
An imaging apparatus control method according to the present invention includes a focus lens that performs focus adjustment, a focus lens driving unit that drives the focus lens, an imaging unit that photoelectrically converts a subject image formed through the focus lens, Extraction means for extracting a high-frequency component of a luminance signal obtained from the imaging means; and operating means capable of selecting an arbitrary maximum value position when there are a plurality of maximum value positions of the high-frequency component extracted by the extraction means; And a method of moving the focus lens to a maximum value position that satisfies a predetermined criterion when there are a plurality of maximum value positions of high-frequency components extracted by the extraction unit. And a procedure for moving the focus lens to the selected local maximum position when the local maximum position is selected by the operating means. Characterized in that it.
The computer program according to the present invention includes a focus lens that performs focus adjustment, a focus lens driving unit that drives the focus lens, an imaging unit that photoelectrically converts a subject image formed through the focus lens, and the imaging unit. Extraction means for extracting the high frequency component of the luminance signal obtained from the above, and operation means capable of selecting an arbitrary maximum value position when there are a plurality of maximum value positions of the high frequency component extracted by the extraction means. A computer program for controlling an imaging apparatus, wherein when there are a plurality of maximum value positions of high-frequency components extracted by the extraction means, a process of moving the focus lens to a maximum value position that satisfies a predetermined reference; When the local maximum position is selected by the operating means, the focus is set to the selected local maximum position. Characterized in that to execute a process of moving the lens to the computer.

  According to the present invention, even when there are a plurality of subjects at different distances, the photographer can select the focus position. Therefore, only one image is recorded by one photographing operation, and the photographer can achieve the position intended by the photographer. An image in focus can be obtained.

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.
(First embodiment)
FIG. 1 is a block diagram showing a schematic configuration of an electronic camera according to an embodiment to which the present invention is applied. Reference numeral 101 denotes a focus lens for focusing on the image sensor 112. Reference numeral 102 denotes a photo interrupter that detects the initial position of the focus lens 101. Reference numeral 103 denotes a motor for driving the focus lens 101. Reference numeral 104 denotes a focus lens drive circuit that inputs a drive signal to the motor 103 and moves the focus lens 101.

  Reference numeral 105 denotes a light amount control member such as an aperture or a shutter. A motor 106 drives the diaphragm and shutter 105. Reference numeral 107 denotes an aperture / shutter drive circuit that inputs a drive signal to the motor 106 and moves the shutter 105.

  A zoom lens 108 changes the focal length of the photographing lens. Reference numeral 109 denotes a photo interrupter that detects the initial position of the zoom lens 108. A motor 110 drives the zoom lens 108. Reference numeral 111 denotes a zoom lens drive circuit that inputs a drive signal to the motor 110 and moves the zoom lens 108.

  An image sensor 112 converts reflected light from the subject into an electrical signal. Reference numeral 113 denotes an A / D converter that converts an analog signal output from the image sensor 112 into a digital signal. A timing signal generation circuit 114 generates a timing signal necessary for operating the image sensor 112 and the A / D converter 113.

  Reference numeral 115 denotes an image processing processor that performs predetermined processing on the image data input from the A / D converter 113. The image processor 115 also functions as an extraction unit that extracts a high-frequency component of the luminance signal obtained from the image sensor 112.

  A buffer memory 116 temporarily stores the image data processed by the image processor 115. Reference numeral 117 denotes an interface for connection with the recording medium 118. Reference numeral 118 denotes a recording medium such as a memory card or a hard disk.

  Reference numeral 119 denotes a system control CPU for controlling the entire system such as an imaging sequence. Reference numeral 120 denotes a zoom switch for instructing the start and stop of the zoom operation. Reference numeral 121 denotes a shooting preparation instruction switch SW1 for instructing shooting preparation such as AF (automatic focus) and AE (automatic exposure). Reference numeral 122 denotes a photographing processing instruction switch SW2 for instructing photographing processing such as main exposure and recording operation after the shadow preparation instruction switch 121 is operated. Reference numeral 123 denotes a main switch for turning on the power. Reference numeral 124 denotes a mode switch for setting the operation mode of the camera.

  A program memory 125 stores a program executed by the system control CPU 119. A work memory 126 writes and reads various necessary data when the system control CPU 119 performs processing according to a program stored in the program memory 125.

  Reference numeral 127 denotes an operation display unit for displaying an operation state of the camera and various warnings. An electronic viewfinder EVF 128 displays an image. Reference numeral 129 denotes a setting switch for performing various settings. Reference numeral 130 denotes a speaker for outputting various warning sounds, operation sounds, and voices.

  Reference numeral 131 denotes a cross switch for moving the selection frame when a distance measurement frame to be described later is selected. Reference numeral 132 denotes a peak position movement switch for moving the maximum value position (peak position) within the selected distance measuring frame.

  Next, basic processing operations in the electronic camera will be described with reference to the flowchart of FIG. In step S201, the state of the shooting preparation instruction switch 121 (SW1) is determined.

  In step S202, the AE operation is performed so that the brightness of the image displayed on the EVF 128 becomes appropriate by controlling the aperture value and the shutter speed. In step S203, an auto white balance (AWB) operation is performed so that an image displayed on the EVF 128 has an appropriate color balance regardless of the color temperature of the light source. In step S204, the image signal read from the image sensor 112 is subjected to predetermined processing and displayed on the EVF 128.

  In step S205, photographing processing is performed according to the flowchart of FIG.

  FIG. 3 is a flowchart illustrating the photographing process in step S205 of FIG. In step S301, a main exposure AE operation is performed. In step S302, the main exposure AF operation is performed according to the flowcharts of FIGS. 4A and 4B. In step S303, in-focus position selection processing is performed according to the flowchart of FIG. In step S304, the state of the photographing preparation instruction switch 121 (SW1) is determined. If it is ON, the process proceeds to step S305, and if not, this process ends. In step S305, the state of the photographing processing instruction switch 122 (SW2) is determined. If it is ON, the process returns to step S306, and if not, the process returns to step S303. In step S306, the main exposure and recording are performed according to the flowchart of FIG.

  4A and 4B are flowcharts for explaining the main-exposure AF operation in step S302 of FIG. In step S401, the data acquisition index is stored as 0 in the work memory 126. This data acquisition index is used to indicate the acquisition and storage order and the total number of acquisition and storage data when storing a focus evaluation value and the position of the focus lens 101 described later in the work memory 126.

  In step S402, the focus lens 101 is moved to the scan start position. The scan start position is, for example, the infinite end of the focusable area. In step S403, the analog video signal read from the image sensor 112 is converted into a digital signal via the A / D converter 113, and the high-frequency component of the luminance signal is extracted by the image processor 115, which is used as the focus evaluation value. Is stored in the work memory 126. At this time, when a plurality of distance measurement frames are set as shown in FIG. 17, a focus evaluation value is stored for each distance measurement frame.

  In step S404, the current position of the focus lens 101 is acquired and stored in the work memory 126. When a stepping motor is used for the focus lens drive motor 103, the position of the focus lens 101 is determined by the number of relative drive pulses from the initial position detected by the photo interrupter 102. Moreover, you may make it measure an absolute position using the rotary encoder etc. which are not shown in figure.

  In step S405, 1 is added to the data acquisition index and the result is stored in the work memory 126. In step S406, it is determined whether or not the current position of the focus lens 101 is equal to the scan end position. If they are equal, the process proceeds to step S408, and if not, the process proceeds to step S407. The scan end position is, for example, the closest end of the focusable area.

  In step S407, the focus lens 101 is moved by a predetermined amount in the scan end direction.

  Moving to FIG. 4B, in step S408, the distance measurement frame index is set to 0 and stored in the work memory 126. This distance measurement frame index is used to identify a plurality of distance measurement frames.

  In step S409, the increase flag is stored in the work memory 126 as FALSE. This increase flag indicates whether or not the acquired focus evaluation value has increased with respect to the previous focus evaluation value.

  In step S410, the data comparison index n is stored as 0 in the work memory 126. This data comparison index n is used to indicate the order of the acquired focus evaluation values when comparing the magnitude relationship of the focus evaluation values acquired in step S403 and stored in the work memory 126.

  In step S411, it is determined whether or not the (n + 1) th focus evaluation value is larger than the nth focus evaluation value. That is, the magnitude relationship between a certain focus evaluation value and the focus evaluation value acquired one after is compared. If the (n + 1) th focus evaluation value is larger than the nth focus evaluation value, the process proceeds to step S412, and if not, the process proceeds to step S415.

  In step S412, the increase flag is set to TRUE. In step S413, 1 is added to the data comparison index n. In step S414, it is determined whether or not the data comparison index n is equal to the data acquisition index-1. If so, the process proceeds to step S418, and if not, the process returns to step S411.

  In step S415, it is determined whether or not the increase flag is TRUE. If TRUE, the process proceeds to step S416, and if not, the process proceeds to step S417. In step S416, the lens position corresponding to the current data comparison index n is stored as the local maximum position. That is, the position of the focus lens 101 stored in the nth work memory 126 is stored in the work memory 126 as a maximum value position. In step S417, the increase flag is set to FALSE, and the process proceeds to step S413.

  In step S418, 1 is added to the distance measurement frame index. In step S419, it is determined whether or not the distance measurement frame index is a predetermined value. If it is a predetermined value, the process returns to step S420, and if not, the process returns to step S409.

  In step S420, the focus lens 101 is moved to the first maximum value position among the maximum value positions stored in step S416. The procedure for selecting the first local maximum position is as follows. First, the position closest to the closest end among the local maximum positions in each distance measurement frame is selected for each distance measurement frame. Next, a distance measurement frame indicating a position closest to the closest end is selected from the positions of the selected distance measurement frames, and this position is set as a first maximum value position.

  FIG. 5 is a flowchart for explaining the in-focus position selection process in step S303 of FIG. Now, as shown in FIG. 17, it is assumed that nine distance measurement frames are displayed on the EVF 128. In step S501, it is determined whether or not there are a plurality of maximum values in the distance measurement frame selected in step S420 of FIG. 4B. If there are a plurality of local maximum values, the process proceeds to step S502.

  In step S502, it is notified that there are a plurality of maximum values of the currently selected distance measurement frames, that is, that there is a distance conflict. This notification is performed by blinking the currently selected distance measurement frame among the distance measurement frames displayed on the EVF 128. In addition, the display color of the distance measurement frame may be changed, or a warning sound may be emitted from the speaker 130.

  In step S503, the perspective conflict notification for the currently selected distance measurement frame is canceled. If the notification is made by blinking the distance measuring frame, the blinking is stopped. If the notification is made by changing the display color of the distance measurement frame, the display color is made the same as that of the unselected distance measurement frame. If the notification is made by sounding a warning sound, the warning sound is stopped.

  In step S504, it is determined whether or not the cross switch 131 has been operated. If operated, the process proceeds to step S505, and if not, the process proceeds to step S508. The cross switch 131 is a combination of switches arranged vertically and horizontally.

  In step S505, it is determined whether or not there is a focusing frame in the direction in which the cross switch 131 is operated. If there is a focusing frame, the process proceeds to step S506, and if not, this process ends.

  In step S506, the distance measurement frame in the direction in which the cross switch 131 is operated in step S505 is selected. For example, as shown in FIG. 6, when the upper switch of the cross switch 131 is operated in the state where the lower center frame is selected from the nine range frames, one of the currently selected frames. It is determined whether or not the maximum value stored in step S416 in FIG. 4B exists for the upper distance measurement frame. If the maximum value exists, it is considered that there is a subject that can be focused within the distance measurement frame, and the distance measurement frame is selected. If the maximum value does not exist, the distance measurement frame is not regarded as a focusable frame, and the same processing is performed for the next higher distance measurement frame. If the maximum value exists, the distance measurement frame is selected. .

  In step S507, the focus lens 101 is moved to the local maximum position of the distance measurement frame selected in step S506.

  In step S508, the number of local maximum values stored in step S416 in FIG. 4B is determined for the currently selected distance measurement frame. If there are a plurality of local maximum values, the process proceeds to step S509, and if not, this process ends.

  In step S509, the state of the peak position movement switch 132 is determined. If it is ON, the process proceeds to step S510, and if not, this process ends.

  In step S510, the focus lens 101 is moved from the current position to the nearest maximum value position on the infinite end side among the maximum value positions stored in step S416 in FIG. 4B. At this time, you may move to the nearest maximum value position on the closest end side.

  FIG. 7 is a flowchart for explaining the main exposure process in step S306 of FIG. In step S701, the image sensor 112 is exposed. In step S702, data stored in the image sensor 112 is read. In step S703, the analog signal read from the image sensor 112 via the A / D converter 113 is converted into a digital signal. In step S704, the image processor 115 performs various image processing on the digital signal output from the A / D converter 113. In step S705, the image processed in step S704 is compressed according to a format such as JPEG. In step S706, the data compressed in step S705 is recorded on the recording medium 118 attached to the electronic camera body via the recording medium interface 117.

  As described above, in steps S403 to S407 in FIG. 4A, the focus lens 101 is moved by a predetermined amount from the infinite end to the closest end of the focusable region, and the focus evaluation value for each distance measuring frame is acquired. Repeat that.

  Next, in step S411 to step S417 in FIG. 4B, the focus evaluation value acquired at a certain time point is sequentially compared with the focus evaluation value acquired next. When the change changes from increase to decrease, the focus evaluation value at that position is regarded as a maximum value, and the position of the focus lens 101 is stored. In this way, the position (maximum value position) of the focus lens 101 at which the focus evaluation value exhibits the maximum value is stored in the work memory 126. This is also performed for each distance measurement frame.

  For example, assume that the relationship between the position of the focus lens 101 and the acquired focus evaluation value is as shown in FIG. In this case, the maximum value of the upper center frame is two, the maximum value of the middle center frame and the lower center frame is one each, and the maximum value is four in total. FIG. 8 shows three in the center row in which nine ranging frames are arranged as shown in FIG.

  Now, if the position closest to the closest end (first maximum value position) is selected among the maximum value positions of all the distance measurement frames in step S420 in FIG. 4B, the maximum value position 4 in FIG. 8 is obtained. Therefore, when the main exposure AF operation is finished, the focus lens 101 is moved to the local maximum position 4 which is the focus position in the lower center frame.

  In this state, when the upper switch of the cross switch 131 is operated as shown in FIG. 6, focusing is possible for the middle center frame, which is the distance measuring frame one level above the lower center frame, which is the current focusing frame. Check whether or not. The focus evaluation value of the middle center frame is as shown in FIG. 8, and since the maximum value exists, focusing is possible. Therefore, the focusing frame moves to the middle stage center frame, and the focus lens 101 moves to the maximum value position 3 that is the maximum value position of the middle stage center frame.

  Further, when the upper switch of the cross switch 131 is operated, similarly, it is checked whether or not focusing is possible with respect to the upper center frame which is a distance measuring frame one above the middle center frame which is the current focusing frame. The focus evaluation value of the upper center frame is as shown in FIG. 8, and since the maximum value exists, focusing is possible. Therefore, the focusing frame moves to the upper central frame, and the focus lens 101 moves to the local maximum position 2 on the closest side of the two local maximum positions of the upper central frame.

  Next, when the peak position movement switch 132 is operated, the focus lens 101 is moved to the maximum value position 1 because there are two maximum value positions of the upper center frame which is the current focusing frame. FIG. 8 shows two examples of the maximum value position. When there are three or more maximum value positions, the position moves to the nearest maximum value position on the infinite end side every time the peak position movement switch 132 is operated.

  As described above, the photographer can select a desired focus position from among the focus positions of each distance measurement frame in a state where a plurality of distance measurement frames are set. It is possible to obtain an image with a single image. In addition, even when there are a plurality of in-focus positions within one distance measurement frame, the photographer can select a desired in-focus position from among the in-focus areas, so one image focused on the desired subject can be obtained. It can be obtained by shooting.

(Second Embodiment)
In the first embodiment, when the photographer operates the cross switch 131, the focusing frame is moved accordingly, and when the peak position movement switch 132 is operated, the focusing position is changed within one distance measuring frame accordingly. Is configured to move between a plurality of local maximum positions. In this embodiment, it is configured to move the focusing frame and move between a plurality of maximum value positions within one distance measuring frame only by operating the peak position moving switch 132.

  FIG. 9 is a modification of the flowchart for explaining the in-focus position selection process of FIG. 5 in the first embodiment. In step S901, it is determined whether or not there is a local maximum position in addition to the currently selected local maximum position. If there is, the process is terminated. In step S902, it is determined whether or not the peak position movement switch 132 has been operated. If it has been operated, the process proceeds to step S903, and if not, this process ends. In step S903, the local maximum position closest to the infinite end side from the current position is selected. This selection method will be described later. In step S904, the focus lens 101 is moved to the local maximum position selected in step S903.

  As described in step S420 of FIG. 4B of the first embodiment, the current position of the focus lens 101 is the closest position to the closest end among the maximum value positions of all the distance measurement frames (first maximum value position). Suppose that The position of the focus lens 101 at this time is a maximum value position 4 in FIG.

  In this state, when the peak position movement switch 132 is operated, the local maximum position closest to the infinity side from the current position is selected from among the local maximum positions in all the distance measurement frames. In FIG. 8, the maximum value position 3 corresponds to this. Thereafter, the focus lens 101 is moved to the maximum value position 3.

  When the peak position movement switch 132 is operated again, the local maximum position closest to the infinite end from the local maximum position 3 that is the current position is selected from among the local maximum positions in all the distance measurement frames. In FIG. 8, the maximum value position 2 corresponds to this. Thereafter, the focus lens 101 is moved to the maximum value position 2.

  In this way, each time the peak position movement switch 132 is operated, the focus lens 101 is moved to the nearest maximum value position on the infinite end side of all the distance measurement frames. Therefore, the photographer can select the in-focus position by operating only the peak position moving switch 132, and an image in which a desired subject is in focus can be obtained by single photographing.

  In step S420 in FIG. 4B of the first embodiment, the first maximum value position may be set to the maximum value position closest to the infinite end among the maximum value positions of all the distance measurement frames. In this case, every time the peak position movement switch 132 is operated, the focus lens 101 may be moved to the nearest maximum value position on the closest end side in the entire distance measurement frame.

(Third embodiment)
In the second embodiment, when the photographer operates the peak position movement switch 132, the in-focus position is moved in the order from the closest side or the infinite side of the maximum value position. In the present embodiment, this is configured to move in the order of the maximum value.

  FIG. 10 is a modification of the flowchart for explaining the focus position selection process of FIG. 5 in the first embodiment. In the following description, in step S420 in FIG. 4B of the first embodiment, it is assumed that the first local maximum position is the local maximum position indicating the maximum value among the local maximum values of all the distance measurement frames.

  In step S1001, it is determined whether or not there is a local maximum position other than the currently selected local maximum position. In step S1002, it is determined whether or not the peak position movement switch 132 has been operated. If it has been operated, the process proceeds to step S1003, and if not, this process ends. In step S1003, the local maximum position of the focus evaluation value that is next to the focus evaluation value at the current position is selected. This selection method will be described later. In step S1004, the focus lens 101 is moved to the local maximum position selected in step S1003.

  As described above, the first maximum value position in step S420 of FIG. 4B of the first embodiment is set as the maximum value position indicating the maximum value among the maximum values of all the distance measurement frames. The current position of the focus lens 101 at this time is the maximum value position 4 in FIG. In FIG. 11, it is assumed that the relationship between the maximum values 1, 2, 3, 4 is such that the maximum value 1 <the maximum value 2 <the maximum value 3 <the maximum value 4.

  In this state, when the peak position moving switch 132 is operated, a local maximum position having the next largest focal point evaluation value after the focal point evaluation value at the current position is selected from among the local maximum position in all the distance measurement frames. In FIG. 11, the maximum value position 3 corresponds to this. Thereafter, the focus lens 101 is moved to the maximum value position 3.

  When the peak position movement switch 132 is operated again, the local maximum position having the next largest focal point evaluation value after the focal point evaluation value at the current position is selected from the local maximum value positions in all the distance measurement frames. In FIG. 11, the maximum value position 2 corresponds to this. Thereafter, the focus lens 101 is moved to the maximum value position 2.

  In this way, each time the peak position moving switch 132 is operated, the focus lens 101 is moved in the descending order of the focus evaluation value among the maximum value positions of all the distance measurement frames. Therefore, the photographer can select the in-focus position by operating only the peak position moving switch 132, and an image in which a desired subject is in focus can be obtained by single photographing.

(Fourth embodiment)
In the first to third embodiments, the method for selecting the in-focus position has been described. In the present embodiment, a method for confirming the focus at the in-focus position after selection will be described.

  FIG. 12 is a modification of the flowchart for explaining the focus position selection process of FIG. 5 in the first embodiment. In step S1201, it is determined whether or not there are a plurality of maximum values in the distance measurement frame selected in step S420 of FIG. 4B.

  In step S1202, it is notified that there are a plurality of maximum values of the currently selected distance measurement frames, that is, that there is a perspective conflict. This notification is performed by blinking the currently selected distance measurement frame among the distance measurement frames displayed on the EVF 128. In addition, the display color of the distance measurement frame may be changed, or a warning sound may be emitted from the speaker 130.

  In step S1203, the perspective conflict notification for the currently selected distance measurement frame is canceled. If the notification is made by blinking the distance measuring frame, the blinking is stopped. If the notification is made by changing the display color of the distance measurement frame, the display color is made the same as that of the unselected distance measurement frame. If the notification is made by sounding a warning sound, the warning sound is stopped.

  In step S1204, it is determined whether or not the cross switch 131 has been operated. If operated, the process proceeds to step S1205, and if not, the process proceeds to step S1210.

  In step S1205, it is determined whether or not there is a focusing frame in the direction in which the cross switch 131 is operated. If there is a focusing frame, the process proceeds to step S1206. Otherwise, the process ends.

  In step S1206, a distance measurement frame in the direction in which the cross switch 131 is operated in step S1205 is selected. For example, as shown in FIG. 6, when the upper switch of the cross switch 131 is operated in the state where the lower center frame is selected from the nine range frames, one of the currently selected frames. It is determined whether or not the maximum value stored in step S416 in FIG. 4B exists for the upper distance measurement frame. If the maximum value exists, it is considered that there is a subject that can be focused within the distance measurement frame, and the distance measurement frame is selected. If the maximum value does not exist, the distance measurement frame is not regarded as a focusable frame, and the same processing is performed for the next higher distance measurement frame. If the maximum value exists, the distance measurement frame is selected. .

  In step S1207, the focus lens 101 is moved to the local maximum position of the distance measurement frame selected in step S1206.

  In step S1208, the display of the subject image on the EVF 128 is changed to a focus confirmation display by a method described later.

  In step S1209, the current time is stored in the work memory 126 as the time when the focus confirmation display is started.

  In step S1210, the number of local maximum values stored in step S416 in FIG. 4B is determined for the currently selected distance measurement frame. If there are more than one, the process proceeds to step S1211. Otherwise, the process ends.

  In step S1211, the state of the peak position movement switch 132 is determined. If it is ON, the process proceeds to step S1212. If not, this process ends.

  In step S1212, the focus lens 101 is moved from the current position to the nearest maximum value position on the infinite end side among the maximum value positions stored in step S416 in FIG. 4B, and then the process proceeds to step S1208.

  FIG. 13 is a modification of the flowchart for explaining the photographing process of FIG. 3 in the first embodiment. In step S1301, the main exposure AE operation is performed. In step S1302, the main exposure AF operation is performed according to the flowcharts of FIGS. 4A and 4B of the first embodiment.

  In step S1303, the subject image displayed on the EVF 128 is changed to a focus confirmation display by a method described later. In step S1304, the current time is stored in the work memory 126 as the time when the focus confirmation display is started.

  In step S1305, in-focus position selection processing is performed according to the flowchart of FIG. In step S1306, the state of the photographing preparation instruction switch 121 (SW1) is determined. If it is ON, the process proceeds to step S1308; otherwise, the process proceeds to step S1307. In step S1307, the focus confirmation display described in step S1208 of FIG.

  In step S1308, the state of the photographing processing instruction switch 122 (SW2) is determined. If ON, the process proceeds to step S1309, and if not, the process proceeds to step S1311. In step S1309, the focus confirmation display described in step S1208 of FIG. 12 is restored. In step S1310, the main exposure and recording are performed according to the flowchart of FIG.

  In step S1311, the current time is stored in the work memory 126. In step S1312, it is determined whether or not the difference between the current time stored in step S1311 and the start time of focus confirmation display stored in step S1304 or step S1209 in FIG. As a result, if it is equal to or greater than the predetermined value, the process proceeds to step S1313, and if not, the process proceeds to step S1305. In step S1313, the focus confirmation display described in step S1208 of FIG. 12 is restored, and the process returns to step S1405.

  Next, a method of changing the display of the subject image on the EVF 128 in step S1303 of step S1208 in FIG. 12 to display for focus confirmation will be described. First, among the nine distance measurement frames as shown in FIG. 14, for example, when the center distance measurement frame is selected, the image in the center distance measurement frame is enlarged and displayed as shown in FIG. Similarly, when another distance measurement frame is selected, the image in the selected distance measurement frame is enlarged and displayed.

  If there are a plurality of maximum focus evaluation values within the currently selected distance measurement frame, the image within the distance measurement frame is enlarged if the peak position movement switch 132 is operated to move the maximum value position. To display. At that time, the time at this time is stored in the work memory 126 as described in step S1209 and step S1304.

  Next, before the photographing processing instruction switch 122 (SW2) is turned on and the main exposure processing is started, the enlarged image is returned to the original display. This has been described in step S1309 in FIG. Even when the photographing processing instruction switch 122 (SW2) is not turned on, if the photographing preparation instruction switch 121 (SW1) is kept on, the image is returned to the original display after a predetermined time has elapsed. This has been described in steps S1311 to S1313 in FIG.

  In this manner, the in-focus state of the subject can be confirmed by enlarging and displaying the image of the selected distance measurement frame. In addition, by selecting a distance measurement frame, it is possible to confirm the focus state of the subject with respect to the plurality of distance measurement frames. Further, when there are a plurality of maximum focus evaluation values within the same distance measurement frame, the in-focus state of the subject at each maximum value position can be confirmed.

  In order to check the in-focus state, the aperture may be opened from the current opening position instead of enlarging the image. In this case, since the depth of field becomes shallow by opening the aperture, it is easy to check the in-focus state of the subject.

  Further, in order to confirm the in-focus state, the subject image on the EVF 128 may be contour-enhanced instead of enlarging the image. In this case as well, the in-focus state of the in-focus subject is emphasized by enhancing the outline, so that the in-focus state of the subject can be easily confirmed.

  An object of the present invention is to supply a storage medium storing software program codes for realizing the functions of the above-described embodiments to a system or apparatus, and the computer (or CPU or MPU) of the system or apparatus stores the storage medium. Needless to say, this can also be achieved by reading and executing the program code stored in.

  In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the program code itself and the storage medium storing the program code constitute the present invention.

  As a storage medium for supplying the program code, for example, a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

  Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an OS (basic system or operating system) running on the computer based on the instruction of the program code. Needless to say, a case where the functions of the above-described embodiment are realized by performing part or all of the actual processing and the processing is included.

  Further, after the program code read from the storage medium is written to a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function expansion is performed based on the instruction of the program code. It goes without saying that the CPU or the like provided in the board or function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.

It is a block diagram which shows schematic structure of the electronic camera which concerns on embodiment. It is a flowchart for demonstrating the basic processing operation in an electronic camera. It is a flowchart explaining the imaging | photography process in 1st Embodiment. 5 is a flowchart for explaining a main exposure AF operation in the first embodiment. 5 is a flowchart for explaining a main exposure AF operation in the first embodiment. It is a flowchart explaining the focus position selection process in 1st Embodiment. It is a figure explaining ranging frame selection. It is a flowchart explaining the main exposure process in 1st Embodiment. It is a figure explaining the focus evaluation value with respect to several ranging frames. It is a flowchart explaining the focus position selection process in 2nd Embodiment. It is a flowchart explaining the focus position selection process in 3rd Embodiment. It is a figure explaining the focus evaluation value with respect to several ranging frames. It is a flowchart explaining the focus position selection process in 4th Embodiment. It is a flowchart explaining the imaging | photography process in 4th Embodiment. It is a figure explaining the image display for a focus confirmation in 4th Embodiment. It is a figure explaining the image display for a focus confirmation in 4th Embodiment. It is a figure which shows the example which used the center part of the imaging | photography screen as the ranging frame. It is a figure which shows the example which set the some ranging frame on the imaging | photography screen. It is a characteristic view which shows an example of the relationship between a lens position and a focus evaluation value. It is a characteristic view which shows an example of the relationship between a lens position and a focus evaluation value.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Focus lens 103 Focus lens drive motor 104 Focus lens drive circuit 105 Light quantity control members, such as a diaphragm and a shutter 108 Zoom lens 112 Image pick-up element 114 Timing signal generation circuit 115 Image processor 119 System control CPU
126 Work memory 128 Electronic viewfinder 131 Cross switch 132 Peak position movement switch

Claims (17)

A focus lens to adjust the focus;
Focus lens driving means for driving the focus lens;
Imaging means for photoelectrically converting a subject image formed through the focus lens;
Extraction means for extracting a high-frequency component of a luminance signal obtained from the imaging means;
Control means for controlling movement of the focus lens via the focus lens driving means;
An imaging apparatus comprising: an operation unit capable of selecting an arbitrary maximum value position when there are a plurality of maximum value positions of the high-frequency component extracted by the extraction unit.   The imaging apparatus according to claim 1, wherein a plurality of regions from which high-frequency components are extracted are set by the extraction unit.   The operation means includes a first operation member that selects a region, and a second operation member that selects a maximum value position in the region selected by the first operation member. The imaging device according to claim 2.   When there are a plurality of maximum value positions of the high-frequency components extracted by the extraction means, the control means moves the focus lens to a maximum value position closest to the closest end as the first maximum value position. The imaging apparatus according to claim 1, wherein the imaging apparatus is characterized.   The operation means is constituted by one operation member, and when the operation member is operated, the control means moves the focus lens from the current maximum value position to the nearest maximum value position on the infinite end side. The imaging apparatus according to claim 4, wherein the imaging apparatus is characterized.   The control means moves the focus lens to a maximum value position closest to the infinite end as a first maximum value position when there are a plurality of maximum value positions of the high frequency components extracted by the extraction means. The imaging apparatus according to claim 1 or 2.   The operation means is constituted by one operation member, and when the operation member is operated, the control means moves the focus lens from the current maximum value position to the nearest maximum value position on the closest end side. The imaging apparatus according to claim 6.   The control means moves the focus lens to a maximum value position indicating a maximum value as a first maximum value position when there are a plurality of maximum value positions of the high-frequency component extracted by the extraction means. The imaging apparatus according to claim 1 or 2.   The operation means is composed of one operation member, and when the operation member is operated, the control means moves the focus lens from the current maximum value position to a maximum value position indicating the next largest value. The imaging apparatus according to claim 8, wherein the imaging apparatus is characterized. Display means for displaying a subject image output from the imaging means;
Magnifying means for magnifying the subject image displayed on the display means,
10. The imaging apparatus according to claim 1, wherein when the focus lens is moved to a maximum value position selected by the operation unit, a subject image is enlarged and displayed on the display unit. . A shooting preparation instruction means for instructing shooting preparation;
The imaging apparatus according to claim 10, wherein after the subject image is enlarged and displayed on the display unit, the enlarged display is stopped when there is no instruction to prepare for imaging by the imaging preparation instruction unit. A shooting process instruction means for instructing the shooting process;
12. The imaging apparatus according to claim 10 or 11, wherein after the subject image is enlarged and displayed on the display unit, the enlarged display is stopped when the imaging processing instruction unit instructs the imaging process.   The imaging apparatus according to claim 10, wherein after the subject image is enlarged and displayed on the display unit, the enlarged display is stopped when a predetermined time has elapsed. Display means for displaying a subject image output from the imaging means;
A diaphragm for limiting a light beam incident on the image pickup means from a subject,
The imaging apparatus according to claim 1, wherein the aperture is opened when the focus lens is moved to a maximum value position selected by the operation unit. Display means for displaying a subject image output from the imaging means;
Contour emphasizing means for emphasizing the contour of the subject image displayed on the display means,
10. The outline of a subject image displayed on the display unit is emphasized when the focus lens is moved to a maximum value position selected by the operation unit. Imaging device. A focus lens that performs focus adjustment, a focus lens driving unit that drives the focus lens, an imaging unit that photoelectrically converts a subject image formed through the focus lens, and a high-frequency of a luminance signal obtained from the imaging unit An imaging apparatus control method comprising: extraction means for extracting a component; and operating means capable of selecting an arbitrary maximum value position when there are a plurality of maximum value positions of high-frequency components extracted by the extraction means. And
A procedure for moving the focus lens to a maximum value position that satisfies a predetermined criterion when there are a plurality of maximum value positions of the high-frequency components extracted by the extraction means;
And a procedure for moving the focus lens to the selected maximum value position when the maximum value position is selected by the operation means. A focus lens that performs focus adjustment, a focus lens driving unit that drives the focus lens, an imaging unit that photoelectrically converts a subject image formed through the focus lens, and a high-frequency of a luminance signal obtained from the imaging unit A computer program for controlling an imaging apparatus comprising: extraction means for extracting a component; and operating means capable of selecting an arbitrary maximum value position when there are a plurality of maximum value positions of high-frequency components extracted by the extraction means Because
A process of moving the focus lens to a maximum value position that satisfies a predetermined criterion when there are a plurality of maximum value positions of the high-frequency component extracted by the extraction unit;
A computer program for causing a computer to execute a process of moving the focus lens to a selected maximum value position when a maximum value position is selected by the operation means.

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